Modern aircraft often use a variety of high lift leading and trailing edge devices to improve high angle of attack performance during various phases of flight, including takeoff and landing. Existing leading edge devices include leading edge slats and Krueger flaps. Current leading edge slats generally have a stowed position in which the slat forms a portion of the leading edge of the wing, and one or more deployed positions in which the slat extends forward and down to increase the camber and/or planform area of the wing. The stowed position is generally associated with low drag at low angles of attack and can be suitable for cruise and other low angle of attack operations. The extended position(s) is/are generally associated with improved airflow characteristics over the aircraft's wing at higher angles of attack. Typical leading edge slat designs include arrangements in which the leading edge device retracts in an aft direction to form the leading edge of the wing when stowed. Krueger flaps have generally the same function as leading edge slats, but rather than retracting aft to form the leading edge of the wing, Krueger flaps typically fold into the lower surface of the wing when stowed.
In some cases, a slot or gap is created between the leading edge device and the wing as the device extends. During certain operating conditions, air can flow through this slot to energize the airflow over the upper surface of the wing, and improve overall airflow characteristics over the wing. A drawback with current systems is that it can be difficult to properly form and/or properly place the gap to achieve the desired flow characteristics proximate to the leading edge device. Another drawback associated with Krueger flap arrangements is that it may be difficult to form a gap that is large enough to achieve the desired airflow characteristics, without requiring complex and/or structurally inefficient linkage mechanisms.